The use of electronic reproduction devices for reproducing authorization data using a user interface in the form of a display has the advantage that no one-off paper tickets need to be produced and distributed. Electronic reproduction devices for reproducing authorization data have the advantage that they can be used multiple times and for obtaining various services or for accessing various systems or buildings. In addition, electronic reproduction devices can be provided with communication modules, so that authorization data can be loaded dynamically into the reproduction devices via a telecommunication network.
Patent application DE 100 34 275 describes an authorization verification method in which access authorizations are transmitted via a mobile radio network to a mobile device, where they are shown on the display such that they can be (machine-)read by a barcode reader.
Patent application US 2003/0054801 describes an authorization verification method in which access authorizations are transmitted via a mobile radio network to a mobile device, where they are shown on a display in graphical form by a user-independent function and can be viewed by the eyes of a verifier. In addition, the verifier can check the authenticity of the graphically shown authorization data, in line with US 2003/0054801, by using a communication terminal to transmit a query to an authorization center. This involves requesting that the authorization data associated with the relevant user or with the relevant mobile device be transmitted from the authorization center to the verifier's communication terminal. To prevent unauthorized copies of the graphically shown authorization data, however, US 2003/0054801 also requires additional machine-readable visual features.
WO 02/48926 describes an authorization verification method in which the authorization verification involves user-specific transaction parameters being requested from a control center. The transaction parameters or a status code which is dependent thereon is/are transmitted from the control center to a verifier's terminal. In line with WO 02/48926, the status code is transmitted to a terminal belonging to the user and is displayed visibly to the verifier, with the status code being regularly renewed by the control center in order to increase security. The verifier's terminal generates the status code on the basis of an identical algorithm, so that both codes are changing continually and in sync but have the same value.